As a cosmetic containing powder, there are a foundation, face powder, a cheek color, an eye color, body powder, etc. Powder referred to as a loading pigment, a white pigment or a coloring pigment is usually formulated in these cosmetics. The loading pigment includes inorganic powder such as talc, kaolin, mica, etc., and organic powder such as protein powder, fish scale guanine, etc. The white pigment includes inorganic powder such as titanium oxide, zinc oxide, etc. The coloring pigment includes inorganic powder such as red oxide, black iron oxide, yellow iron oxide, etc., and organic powder such as lake, tar pigment, etc. The above powders are usually amphiphatic and have properties which are compatible with both water and oil. Therefore, a cosmetic prepared by formulating these powders is liable to get wet by water or a secretion such as sweat, sebum, etc., thereby causing a phenomenon of "change of makeup" wherein a color tone of the cosmetic per se is deteriorated or clarified to expose a color of the skin, or a cosmetic film is transferred and agglomerated by perspiration or a motion of the face.
As a technique of preventing the change of makeup caused by water or sweat, a method comprising surface-treating the powder with silicone to impart water-repellency to the powder has usually been used. However, this method could not prevent the change of makeup caused by sebum because the silicone has water-repellency and has no oil-repellency.
In order to prevent the change of makeup caused by sebum, a method comprising surface-treating the powder with a fluorine-containing compound to impart the water- and oil-repellency to the powder has been recently suggested.
For example, Japanese Patent Kokai Publication No. 250074/1987 (62-250074) discloses a method comprising using diethanolamine perfluoroalkylphosphate as a fluorine-containing compound, which has already been put to practical use. However, this fluorine-containing compound has a problem of the cost that it is very expensive. Another problem of the design is materials. The characteristics of the compound are not easily modified because of non-polymerizability. Also, there is a problem of production. The powder must be surface-treated in water because of its hydrophilic nature and, therefore, the production process becomes complicated.
Japanese Patent Kokai Publication No. 167209/1980 (55-167209) discloses a method comprising using a water- and oil-repellent of a polymer having a perfluoroalkyl group, but there was a problem that the water- and oil-repellency is not always imparted to the powder. Specifically, even if the powder is treated with a solution prepared by diluting a commercially available perfluoroalkyl group-containing acrylate polymer emulsion described in the Example of this Patent Publication with water, many parts of the emulsion are not absorbed on the powder surface and water- and oil-repellency can not be imparted.